The present invention relates to a conveying apparatus.
A roller conveyor, which is one kind of conveying apparatus, has a plurality of feed rollers. A conventional roller conveyor has an induction motor connected to each of the feed rollers. In general, a speed reducer is intervened between each feed roller and the induction motor. The speed reducer however enlarges the roller conveyor. As a solution to this shortcoming, there is a proposal to replace the induction motor with a two-phase synchronous motor. The two-phase synchronous motor supplies each feed roller with a low-speed and high torque without a speed reducer.
The two-phase synchronous motor is driven by two single-phase AC voltages, the first single-phase AC voltage and the second single-phase AC voltage, supplied from a single-phase AC power supply. The second single-phase AC voltage is acquired by shifting the phase of the first single-phase AC voltage by 90° by a capacitor. The capacitor however requires regular maintenance and brings about an increase in the cost of the roller conveyor.